基于自适应扫描的图像压缩方法

Image compression method based on adaptive scanning

现有的压缩方法通常采用固定的扫描方式。然而,每幅图像都有其自身的特点,采用固定扫描难以使其得到好的压缩性能。针对该问题,提出了一种基于自适应扫描的图像压缩方法。首先,对图像进行小波变换后,根据图像内容决定子带间扫描顺序。其次,对于子带内扫描,根据子带特性设计不同的扫描方法,以尽可能保留图像的纹理特征。最后,采用二叉树编码器对扫描后的系数序列进行编码。实验证明,在相同条件下,该方法明显优于主流的JPEG2000,且优于最新的基于固定扫描的自适应二叉树编码方法。

Existing compression schemes usually scan an image by a fixed way.However,each image has its own characteristics,which makes it difficult to obtain a good coding performance with a fixed scanning manner.To solve this problem,an adaptive scanning-based compression method is proposed.Firstly,the wavelet transform is performed.Then the scanning order among the subbands is determined by the content of the image.Secondly,for the scanning of a subband,in order to preserving the texture information as much as possible,the scanning method is designed with the considering of the characteristic of the subband.Finally,the binary tree code is exploited to encode the one-dimensional coefficient sequence.Experiments show that,under the same conditions,the proposed compression method is superior to JPEG2000 and the state-of-the-art compression methods based on binary tree coding adaptively（BTCA）.